Jamaat-e-Islami leader Ghafoor Ahmed and Karachi Bar Association President Muhammad Ali Abbasi were among over 350 political activists and lawyers detained across the country.

There were indications of a possible showdown between President Asif Ali Zardari and his one-time ally Sharif who accused the government of not doing anything to undo what the "kangaroo" courts have done.

"Talks with President Zardari are possible only after he reinstates the judges as promised to us earlier," Sharif said pressing his demand for restoration of independent-minded judges removed by then President Pervez Musharraf during emergency rule in 2007.

Some of them could turn hostile to Zardari, who for this reason, may not have pushed hard for their re-induction, said a report. Zardari also faced pressure from the US, which said Islamabad must respect freedom of speech, expression and assembly.

"What we think is important is that the various parties try to resolve their differences within the political system of Pakistan in accordance with its constitution with respect for the rule of law," US State Department's Acting spokesman Robert Wood said in Washington.

There were reports that the US was trying to bring about reconciliation between the Pakistan government and Sharif. US Ambassador to Pakistan Anne Patterson was trying to get things resolved, claimed Sharif's spokesman Sadiqui Farooq but the American Embassy refused to comment.

Aitzaz Ahsan, a key player in the lawyers' movement and a dissident leader of the ruling Pakistan People's Party, emerged from hiding to address a gathering of lawyers at the Lahore Bar Association.

Ahsan vowed that the lawyers and political parties would stage a sit-in before parliament despite the restrictions imposed by the authorities.

Police near the mausoleum of Pakistan's founder Muhammad Ali Jinnah stopped a rally by the Malir Bar Association in Karachi.

Police arrested 60 activists around the city and outside the High Court, the starting point of the march, resulting in scuffles.